Ultrasonic particle manipulation exploited in on-line infrared spectroscopy of (cell) suspensions

Abstract

An ultrasonic standing wave field of 2 MHz was used to manipulate yeast cells in an on-line flow cell for Fourier transformed mid-infrared spectroscopy (FT-IR) purposes. Results show, that a significant decrease of the undesired formation of biofilms on the attenuated total reflection (ATR) surface was achieved. In addition the time resolution was more than doubled.Anwendung der Ultraschall-Teilchen-Manipulation fü r die Online-Infrarot-Spektroskopie von (Zell-)Suspensionen.Ein 2-MHz-Ultraschallstehwellenfeld wurde verwendet, um Hefezellen in einer Online-Durchflusszelle zu Zwecken der Fouriertransformierten Infrarotspektroskopie (FT-IR) anzuordnen. Die Resultate zeigen, dass eine signifikante Reduktion unerwü nschten Biofilms auf der totalreflektierenden (ATR) Oberflä che erreicht wurde. Darü ber hinaus konnte die Zeitauflö sung mehr als verdoppelt werden.

Acoustofluidics 21: ultrasound-enhanced immunoassays and particle sensors

“…The method was evaluated by comparing the carbohydrate value of absorption as a measure for the settling speed. 42 In the absence of the ultrasonic standing wave, the suspended yeast cells settled slowly on the ATR surface at a constant rate. A maximum was reached after approximately 185 s signalling a complete coverage of the sensitive surface.…”

“…8 represents the growth of the bio-film at the respective times (details in ref. 42). Reliability and robustness are key necessities when industrial applications for online fermentation monitoring are envisaged.…”

In Situ Quantification of Polyhydroxybutyrate in Photobioreactor Cultivations of Synechocystis sp. Using an Ultrasound-Enhanced ATR-FTIR Spectroscopy Probe

“…This prolonged procedure could influence the cells due to oxygen or nutrient limitations, as well as produce biofilms as cells are not efficiently resuspended. To avoid these effects in biotechnological processes ultrasound (US) particle manipulation devices can be used [26].…”